Tear strip structure



Oct. 25, 1966 BUTTERY ETAL 3,281,059

TEAR STRIP STRUCTURE 5 Sheets-Sheet 1 Filed 001:. 25, 1965 fi//ZZOAS fennel h TfizzZ/ zery T/zomaS 2W Broom Oct. 25, 1966 BUTTERY ETAL 3,281,059

TEAR STRIP STRUCTURE Filed Oct. 25, 1965 s Sheets- Sheet 2 Oct. 25, 1966 BUTTERY EI'AL 3,281,059

TEAR STRIP STRUCTURE Filed Oct- 23, 1965 V 5 Sheets-Sheet 5 United States Patent 3,281,059 TEAR STRIP STRUCTURE Kenneth T. Buttery and Thomas W. Froom, both of Kalamazoo, Mich., assignors, by mesne assignments, to Brown Company, a corporation of Delaware Filed Oct. 23, 1965, Ser. No. 503,432 12 Claims. (Cl. 22951) The present invention relates to cartons, and is more particularly concerned with cartons which may be readily and inexpensively erected from integral cut and scored blanks, and which cartons are provided with an improved readily detachable tear strip structure retaining the carton cover .in closed position.

Cartons having a so-called flip top cover hingedly connected to the edge of the rear panel, which may be erected with the cover in sealed condition and which may be readily opened by the removal of a tear strip, have become exceedingly popular, particularly as containers for food items such as ice cream. Once the tear strip is removed, the cover may be opened for access to some or all of the contents, and may be reclosed for further storage until the contents have been completely consumed. Cartons of the type described which have been available in the prior art, although satisfactory in use, have the disadvantage that they are either difficult to construct and seal on automatic machinery or are less positive than desired in their ability to open cleanly and conveniently by a simple removal of the tear strip.

Prior art cartons have been provided with an outer front wall member integral with the cover of the carton,

having its own flaps extending at the ends .thereof. A tear strip is provided as an integral unit and extends from the end of one outer front wall flap, across the outer front wall, and to the end of the opposite outer front wall flap. Such a structure is expensive, difficult to construct into a carton from an integral blank, and requires expensive machinery for the purposes of erection and sealing. Additionally, the structure requires a large amount of paperboard, thus adding to the cost of the materials employed.

More simple cartons have also been disclosed in the art having detachable means for aflixing the cover to .the front wall of the carton, the means comprising an adhesive strip adhesively affixed to the front wall and detachably connected to the cover by means of a tear strip defined by a pair of spaced-apart substantially parallel severance lines. Such structure has been found to be generally satisfactory for the intended purpose. However, the utilization of a separate adhesive panel and a separate detachable tear strip adds materially to the cost of the carton. In an effort to reduce cost, cartons have been devised having a tear strip which also functions as an adhesive strip. Such structure generally comprises a tear strip detachably connected to the cover at a single severance line, and which tear strip is adhesively aflixed to the front wall of the carton at isolated areas. According to latest developments, to facilitate opening and in order to prevent the front wall of the carton from becoming disfigured when the tear strip is removed, the isolated or limited adhesive areas on the carton front wall are generally surrounded with a cut score or slit through the tough outer liner of the carton front wall. Additionally, the area surrounding the adhesive areas is covered with an adhesive-resist or glue-release type of ink to prevent adhesion of the tear strip at other than the desired isolated adhesive areas. Such structures have proved to be relatively successful, their major limitation still residing in the imperfection of the tear strip removal operation. Many times, and particularly with regard to those carton blanks formed last in each cut from a mulj 3,281,059 Patented Oct. 25, .1966

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tiple die, as at the end of each cylindrical cut, the tear strips are not readily and cleanly removable to provide the opened hooded carton.

After many theories, explanations, and unsuccessful attempts to remedy such disadvantage by various approaches and routes, it has now been found that the major reason for this shortcoming is because either the cut scores and the adhesive areas surrounded by the same or the adhesive-resist on glue-release ink pattern and the isolated glue areas defined or surrounded by the cut scores, fail to come into perfect registry, sometimes minutely and sometimes by a greater margin of error. As a result, when the tear strip is removed, the point at which tearing of the paperboard from the carton front wall begins is frequently not at the leading edge of the weakened area defined by the cut score, where such initiation of tearing is desired, the leading edge being that edge located toward the end of the tear strip from which its removal is initiated, but rather at a tougher and unweakened point on'the carton front wall where the outer liner thereof has not been weakened. As a result, portions of the paperboard of the tear strip are torn off and remain affixed to' the front wall of the carton, resulting in an unattractive appearance and sometimes hindering or even preventing the facile opening of the carton by simply pulling upon the tearstrip.

It is an object of the present invention to provide a carton which may be formed from integral cut and scored and preferably mutually nestable blanks. It is a further object to provide a top-opening carton which may be sealed by means of a detachable adhesive strip affixing the cover to the front wall of the carton. It is an additional object to provide a carton having a detachable tear strip of the type described, wherein the tear strip is adhered to the front wall of the carton at localized areas each surrounded by a cut score or slit provided in the front wall of the carton, and which areas are frequently further surrounded by a glue-resist ink. It is a primary object to provide a more satisfactory tear strip opening carton having a tear strip structure embodying means to compensate for lack of registry between the cut-scores surrounding the glue areas and the glue resist ink pattern, when present. It is another object to provide such a carton which may be readily reclosed when it is desired to store unconsu-med contents. It is a still further object to provide a carton of the type described which can be readily erected and subsequently sealed by means of relatively simple and inexpensive machinery. The .accomplishment of .the foregoing and additional objects will become more fully apparent hereinafter.

The invention in its preferred embodiment is illustrated by the accompanying drawings in which:

FIG. 1 is a plan view of a blank cut and scored for assembling a carton according to the invention, and additionally showing a portion of the edge of an adjacent blank nested therewith.

FIG. 2 is a fragmentary plan view of the outer surface of the blank.

FIG. "3 is an enlarged fragmentary View of the cut score shown in FIG. 2.

FIG. 4 is an enlarged fragmentary view of a cut score according to an at-lernative embodiment of the invention.

FIG. 5 is an enlarged fragmentary view of a cut score according to still another embodiment.

FIG. 6 is an enlarged fragmentary view of a cut score according to an additional embodiment.

FIG. 7 is a perspective view of the completely erected and sealed carton.

FIG. 8 is a perspective view of the carton of FIG. 7 after the tear strip has been removed and the cover opened; and

' tion of a preferred embodiment of the tear strip structure of the invention.

According to the invention, a carton is provided which is formed from an integral blank having panels including a bottom member, a front wall member 'hinged-ly connected to one edge of the bottom member, a rear wall member hingedly connected to the other edge of the bottom member, and end flaps hingedly connected to the ends of said members. A cover is provided which is hingedly connected to the upper edge of the rear wall member. The cover is provided with cover flaps comprising cover end wall panels and a cover front wall panel. The cover front wall panel is provided at its ends with end flaps which are adhesively' affixed to the cover end Wall panels. Detachable means is provided at the edge of the cover front wall panel adhesively afiixing the cover frontwall panel to the front wall member comprising a detachable tear strip adhesively afiixed to the front wall member at isolated adhesive areas. In order to facilitate ready separation from, and to prevent defacing of, the front wall member as the tear strip is removed, each adhesive area is surrounded by a primary cut score or slit. Additionally an adhesive-resist ink is usually provided intermediate and surrounding the glue areas to prevent the adhesive,

'as when the adhesive is placed on the tear strip in the form of a single solid strip, from adhering to the areas intermediate the intended glue areas. Such ink is not always present, however, since the adhesive when placed in selected areas on the front wall or tear strip, usually the front wall, may be patterned in hot melt at the same time as 'hot melt is applied to the carton in selected areas for end sealing thereof. Additionally, according to the present invention, a secondary or auxiliary cut score or slit is provided at the leading edge of each glue area with regard to the direction of tear, as already defined, and

spaced apart from the primary cut score a distance sufficient to compensate for any lack of registry which might exist between the primary cut scores and either the glue area or the glue resist ink pattern. This lack of registry and its direction is predictable, at least after the just runthrough on the cylinder bearing the multiple die. Consequently, by providing this secondary cut score, the scored glue areas of the front wall panel will be much more cleanly torn out even when such a substantial lack of registry exists.

As a further embodiment to facilitate clean removal of the tear strip without breakage thereof or defacing the cover front wall panel, the severance line defining one edge of the tear strip may advantageously be provided with a novel configuration. As in certain prior art severance lines, the basic configuration comprises a series of V- or L-shaped slits, each slit having a component colinear with the components of the remaining slits, and another component which is oblique or at an obtuse angle with respect to the first component. The slits forming'the colinear components are spaced apart from each other a short distance to provide bridges which, prior to opening the carton, connect the tear strip with the cover front wall panel. It has now been found, however, that where uniform spacing is utilized between all :adjacents colinear slits which form bridges of suflicient size to withstand tearing under normal use prior to opening of the carton, these bridges frequently offer too much resistance at certain points when the tear strip is pulled off, and thus either cause an intrusion to be made .into the cover front wall panel or else cause breakage of the tear strip. In order to avoid this difliculty, according to a preferred embodiment of the invention, the adjacent colinear components of the slits forming bridges positioned substantially laterally of the leading edges of the cut scores which surround the adhesive areas are elongated, so that each bridge or two locateclsubstantia-lly lateral of the leading edge of the cut score is somewhat reduced. in length and offers considerable less resistance to tear than do the bridges defined by the colinear s-lits of normal length as present at other positions of the tearstrip. Additionally, the initial bridge or two at the tab end 'of the tear strip is preferably reduced in length in the same manner to facilitate initiation of the tearing process. As a result of the combination of these features, the tear strip may be grasped at the tab andreadily and cleanly removed with a single tearing stroke, and without intruding into or disfiguring the cover front wall panel or breakage of the tear strip.

As an additional feature, in order to insure good adhesion between the tear strip and the frontw-all member at the adhesive areas, it has moreover been found desirable to provide areas, and most conveniently rectangular areas, surrounding the adhesive areas which are free of any wax, plastic, or the like, which might be utilized in coating the surface of the carton.

Reference is now made to the accompanying drawings for a better understanding of the invention, wherein all of the parts are numbered,'wherein the same numbers are used to refer to corresponding parts throughout, and wherein areas having an adhesive applied thereto are indicated by stippled shading.

In a preferred form, the carton of the invention is constructed from an integral'blank, as illustrated in FIG. 1, and comprises a bottom panel member 1, a front wall member 2, and a rear wall member 3 hingedly connected to the bottom member 1. A cover 4 is hingedly connected to the rear wall member 3. The bottom 1 is provided at its ends with inner end wall flaps 5 hingedly connected thereto, the front wall member 2 is provided at its ends with front wall outer end flaps 6 hingedly connected thereto,.and the rear wall member 3 is provided with rear wall outer end flaps 7 hingedly connected thereto.

The cover 4 is provided with end flaps 8 comprising cover end wall panels 9 having adhesive panels 10 connected to the panels 9 at severance or fracture lines 11. The cover 4' is also provided at its forward edge with a cover flap 12 comprising a cover front wall panel 13, and a. severance or fracture line 14 defining a detachable tear strip or adhesive panel 15 having a tab or graspable portion 16 at one end thereof. The adhesive panel 15 is adhesively affixed .to the front wall member 2. Adhesion is accomplished at isolated adhesive areas 29 as, for example, in the form of circles, ovals, tear-drops, or rectangles, provided on the surface of the front wall member 2, as shown in FIG. 2, or alternatively on the surface of the adhesive panel 15 in such form.

As previously indicated, the isolated adhesive areas adhering the tear strip 15 to the front wall member 2 may be provided by one of several methods. In one method a solid strip of adhesive 17 is applied to the inner surface of the tear strip 15. The engaging area of the front 1 wall panel is then provided with an adhesive resist coating 30 of a material such as a glue resist ink, wax, or both,

covering the entire area to be engaged by the strip of adhesive 17 except at the isolated adhesive areas 29 which are left free of the adhesive resist coating. Subsequently,

' sion takes place only in the limited areas where the adhesive is present. If desired, placement of the adhesive in both methods may be reversed and the adhesive applied to the outer surface of the front wall member instead of to the tear strip. However, it is generally desirableto utilize the adhesive only on the inner surfaces of the carton blank, since then the adhesive for the entire carton may be applied in one step or pass. ,Consequently,-applying the adhesive to the inner surface of the tear strip 15 is preferred.

In order to prevent unsightly tearing of the outer surface of the front wall member at the adhesive areas 30 and to prevent a portion of the tear strip from being torn off and left adhered to the front wall member when the tear strip tab is pulled, it has proven to be desirable to provide a primary cut score or slit 22 completely surrounding the adhesive area 29. The cut score penetrates the outer surface of the front wall member 2 and extends only partially into the thickness of the carton blank. Consequently, when the tear strip blank is removed, the scored areas offer less resistance to tear than the engaging areas of the tear strip. The presence of the cut scores 22 causes the scored areas to be removed cleanly without leaving unsightly torn edges.

As previously mentioned, it has now been found that, in the preparation of carton blanks of the type described which are provided with isolated adhesive areas defined by an adhesive resist ink pattern designed to be in registry with the primary cut scores, an error in registry is frequently if not generally introduced in the cutting and scoring to produce the blank and in the application of adhesive and/ or adhesive resist ink or other coating, e.g., wax. For example, particularly in the last blanks to be formed on any single pass of paperboard stock through the rotary cutting and printing apparatus, the adhesive resist ink coating tends to overlap a portion 30a of the area within the cut score 22. Such lack of registry resulting in overlapping is shown in FIGS. 2-6 as 30a, 30b, 30c and 30d. Subsequently, when the tear strip is adhered to the front wall member, the area defined within each cut score has a portion thereof covered with adhesive resist ink at the leading edge. These areas of overlap do not adhere to the tear strip. Consequently, when the tear strip is removed, tearing at each isolated area does not begin until the point is reached at which the overlapping coating of adhesive-resist ink stops. Therefore, since the line of discontinuity of the adhesive-resist ink is no longer at the weakened leading edge of the cut score where tearing could easily and cleanly begin, but is instead spaced apart from the cut score and located at a non-weakened point at which tearing of the surface of the paper board can be initiated only with diflicuty, a portion of the tear strip itself is generally ripped off and adheres to the front wall panel in rather ragged and ungainly fashion. This is because, inter alia, when the score line surrounding the intended area of adhesion and the printing is not coincident, the clean removal of the tear strip is rendered much more difficult because the actual adhered area is considerably less than the area within the cut score or alternatively, the adhered area does not correspond to the cut scored area and a break must be made outside of the scored surface, which takes much more pull and puts more strain on the tear strip, and which accordingly also causes greater disfiguration of the carton. According to the present invention, such lack of perfect registry is compensated for by the provision of at least one secondary cut scores 22a, 22b, 220, or 22d at the leading edge of each adhesive area 29 and substantially at the discontinuity line of the adhesive resist ink, when present. After a trial run of any particular blank-forming apparatus setup, the extent and direction of registry error can readily be determined, and the position of the secondary cut score established. Subsequently, the cartons formed at the beginning of each pass and which are generally in perfect registry will have ink boundaries in registry with the primary cut score. With regard to such cartons, when the tear strip is removed, the primary cut score still functions to define the position of the tear out area. As the registry error increases, the secondary cut scores assume more importance in the effective initiation of proper tearing of the adhesive area, which area is now somewhat more limited but still cleanly removed as a result of the 6 presence of the secondary cut score which properly initiates tearing of the adhesive area.

In FIG. 3-6 are shown different forms of secondary cut scores designed to compensate for various types of registry error. In each figure the direction of tear is from right to left, the convention again being used that the edge of the adhesive area which first encounters the tearing process is termed the leading edge.

Referring to FIG. 3, the primary cut score 22 normally defines the adhesive area between the tear strip and the front wall member when there is no registry error between the adhesive resist ink printing and the primary cut score, the adhesive area being the area free of adhesive or glueresist ink. However, in the case of the structure shown in FIG. 3, an area 30a contains overlapping adhesiveresist coating 30 caused by lack of registry, causing a decrease in size of the adhesive area 29a. Consequently, if the secondary cut score 22a were not present, uneven and difiicult tearing would begin at the line where actual adhesion between the area and the glue strip begins, that is, at the discontinuity line of the overlapping ink. The result would be an unsightly jagged edge at each adhesive area or even jagged and unsightly portions of the tear strip remaining affixed to the adhesive area after the tear strip were removed. However, the presence of the secondary cut score 22a provides an additional line of low tear resis-tanance coincident with the adhesive resist ink discontinuity line, so that the adhesive area is cleanly torn out along the line 22a and the remaining portion of the line 22.

In FIG. 4 a secondary cut score 22b is shown in the form of a straight line substantially at the discontinuity line of the overlapping glue resist ink 30b.

In FIG. 5 the secondary cut score 220 is in the form of an arc or curved line spaced apart from the leading edge of the primary cut score 22, and again substantially at the discontinuity of the adhesive resist ink 30, defining an extension 300 of the adhesive area resulting from a registry error, this time in the opposite direction.

In FIG. -6 the secondary cut score 22d is in the form of an oval completely within the primary cut score 22, and substantially at the discontinuity line of the overlapping adhesive resist ink 30d. The structure shown in FIG. 6 may be used to compensate for registry errors in several directions.

Although the present invention has been shown with respect to registry errors between an adhesive resist ink and the primary cut score defining the adhesive are-a, the same secondary cut score structures can be utilized to compensate for registry errors where isolated adhesive bearing areas are utilized which are provided on either the adhesive strip or the carton front wall.

In order to facilitate even cleaner removal of the tear strip, a somewhat modified configuration may be utilized in forming the severance line or fracture score constituting the boundary between the tear strip and the cover front wall panel. As shown in FIG. 9 of the drawings, the severance line 14 comp-rises a plurality of V-shaped cut scores 31 having one horizontal component or leg 32-substantially colinear with the other corresponding legs of the individual scores, and a second component or leg 33 directed obliquely outwardly toward the first leg in the direction of tear and joining an end of the first leg. As a result small uncut bridges .34 remain between the individual cut scores of suflicient size and strength to retain their integrity during normal use of the carton prior to its being opened. According to an improved embodiment of the invention, the horizontal leg 35 of each cut score or two located immediately adjacent laterally to the leading edge of each adhesive area is increased in length, thus forming bridges 36 of reduced length in relation to the normal bridges 34, as show-n in FIG. 9. Additionally the slit structure is so designed that the initial bridge 37 at the end of the tear strip at which tearing is initiated is .made smaller than the normal bridges 34. As a result the clean rem-oval of the tear strip is facilitated.

Referring to the general structure of the carton in its preferred embodiment, the cover front 'wall panel is provided at its ends with end flaps 18, for being affixed to the cover end wall panels 9. The lower portions of the terminal edges of the-rear wall outer end flaps are each provided with an oblique recession 19 receding from the forward-most terminal edge 23 toward the bottom edge of the flap 7 to a vertical edge 23a having the same length as the edge 23. The forward edge 23 should be positioned a sufficient distance from the bottom edge of the flap, or from an imaginary line representing an extension of the score line 25, so that the edge 23 clears the adhesive area 24 when the flaps 6 and 7 are folded together. A rectang-ular corner recess 20 is also provided in the upper terminal corner of the rear outer end wall flap 7 to facilitate nesting of adjacent blanks when they are cut from the paperboard stock, as shown in FIG. 1. The oblique receding edge 19, which should preferably be straight, has a further function in that it permits the oblique edge 19 of an adjacent blank to nest closely therewith, as shown in FIG. 1, accomplishing a material saving in raw material.

In the broader aspects of the invention, the rectangular recess or cut-out 20 may be omitted, thus increasing the vertical dimension of the forward edge 23 of flap 7 or of the oblique recession 19. Although such embodiment does not have the complete blank nesting ability of the embodiment described and illustrated in the drawings, it still retains the advantages that the front edge 23 of the rear wall outer end flap 7 clears the adhesive area 24 of the front wall outer end flap 6, and that it permits the flap 6 to be directly adhered to the inner end wall over a significant segment of its length.

In assembling the carton, the carton blank may be folded at the score line between the bottom 1 and rear wall member 3. The cover front wall panel 13 is then folded over and the adhesive panel 15 afiixed to the outer surface of the front wall member 2, forming a folded tube. Alternatively, the front wall member 2 may be folded over at the score line connecting it with the bottom 1, and the adhesive panel 15 may then be glued to the outer surface of the front wall member 2 in the same man ner. In either form the carton so folded occupies very little space, and may be shipped to the packager in this form for filling and sealing.

To erect the carton further for filling, the folded carton is square-d up, as on a conventional squaring machine. One end isthen closed by first folding in the inner end Wall flap 5. The rear wall outer end flap 7 and the front wall outer end flap 6 are then folded in, the front wall outer end flap overlapping the rear wall outer end flap. The contour provided by the recessed edge 19 permits the terminal edge 23 of the rear wall outer end flap 7 to clear the adhesive area 24 on the inner surface of the outer wall end flap 6. The cover front Wall panel end flap 18 is then folded over, followed finally by the folding over of the cover end Wall panel 9. The greater length of the flap 18 permits it to be engaged and folded over by the plow of the folding apparatus before the panel 9 (of lesser width) is engaged. Heat is then applied to activate and set the adhesive, causing the front wall outer end flap 6 to become adhesively afiixed to the rear Wall outer end flap 7 and also to their inner end Wall flap 5. The adhesive panel 10 becomes adhesively afiixed to the rear wall outer end flap 7 and cover front wall panel end flap 18 becomes aflixed to cover end wall panel 9. The carton may then be filled through the end remaining open.

The opened end may subsequently be closed and sealed in the same manner, to form a completely sealed carton as shown in FIG. 7. Alternatively, the first carton end may be closed and/or tacked, as with glue, but not sealed, and then both carton ends sealed concurrently or simultaneouslyafter fillingof the carton.

The carton may be opened by grasping the tab 16 and removing the tear strip 15. The primary cut scores 22 prevent tearing of the outer surface of the front wall member outside of the areas defined by the cut scores 22. Moreover, the second scores 22a, b, c or d, prevent such tea-ring where a registry error occurs between the glue resist ink and the primary cut scores 22. As the cover is subsequently lifted open, the cover end Wall panels 9 are parted from the tear strips 10 at the severance lines 11, forming the structure shown in FIG. 7. The cover may be reclosed for storing any unconsumed contents.

The adhesive-repellent or resist ink should preferably be one having microcrystalline wax incorporated therein. In order to provide optimum results, the printing must be solid color and not printing formed by means of a dot pattern. The entire outer surface of the carton is desirably pattern-coated with a release agent such as, a wax or plastic coating, excluding the circular, oval, teardrop, or other areas defined by the cut score-s 22, which areas are to be glued to the adhesive strip. In a preferred version, as illustrated in FIG. 2, entire rectangular areas 38 surrounding the adhesive areas 29 should be left free of the Wax or plastic coating. The inner surface of the entire carton may also be coated with a release coating such as wax, excluding the area on the adhesive strip to which an adhesive is subsequently to be appplied. A conventional glue composition is then applied as a solid coating over the inner surface of the tear strip 15. Consequently, when the tear strip 15 is folded over onto the front wall member 2, it becomes adhered to the front wall member only at the tear-drop areas defined by the cut scores 22, which areas are substantially free of any release agent such as wax. If transverse cuts 21 are utilized, they may be positioned intermediate and preferably immediately forward of each adhesive area 29 with respect to the direction of tear. Consequently, when the tear strip 15 is grasped at the tab 16 and removed, it parts cleanly from the front wall member, except in the adhesive zones surrounded by the cut score lines 22, within which zones only the top liner of the front wall panel is removed in the tearing process.

Although either the Wax coating or the glue repellent ink may be used separately as a release agent to prevent adhesion between the adhesive panel 15 and the front Wall member 2, "optimum results are obtained by the use of the combination of both. Moreover, although rectangular areas may be provided free from the release agent at the adhesive zones, excellent results are obtained when the printed application of the release coating is closely patterned around the tear drop areas, substantially exactly in register with the areas of the tear drop. The conventional adhesive, such as glue, is usually laid down as a solid strip on the front wall member from one end of the adhesive strip to the other. Other types of adhesive may be used if desired. Although in the preferred embodiment the adhesive is placed on the strip 15, it may if desired be applied to the front wall member 2. The transverse cuts 21 serve to prevent splitting of the stock as the tear strip zipper is pulled off. However, they may be dispensed with in certain applications.

The carton of the invention has many advantages over prior art cartons. From a general structural viewpoint this carton has the advantages that successive blanks may be positioned and cut in closely nested position, effecting a substantial saving in material costs. Additionally, the terminal edges of the rear wall outer end flaps are so contoured that they do not interfere with the adhesive contained upon the inner surface of the front wall outer end flaps, facilitating the assembly of the carton. Further, the increased length of the cover frontwall panel flaps with respect to the width of the cover end wall panels facilitates their being properly foldedunder the cover end Wall panels using inexpensive machinery or adaptations thereof. More specifically, the carton utilizes a combination tear strip and cover affixing means having isolated areas of adhesion affixing the tear strip to the front wall member of the carton, effecting an appreciable economy in raw materials. Ease of production of the carton blank and assembly thereof are furthered by applying a solid strip of adhesive to the tear strip, and applying a glue resist ink over the general area engaged by the adhesive, but omitting the ink at the isolated areas to be adhered. Cut score lines are provided on the outer surface of the front wall member surrounding the areas intended to be free of the adhesive resist ink. Additionally, according to the invention, secondary cut score lines are provided to compensate for registry errors as between the ink pattern and the primary cut scores, thereby enabling the tear strip to be removed cleanly even where such registry errors occur.

It is thus seen that an economical and conveniently erected and sealed carton of sufficient durability for frequent opening and reclosing is produced, which carton has a structure rendering it adaptable to be produced from integral cut and scored blanks which may be cut out in closely nesting position to conserve paperboard costs. Additionally, efficient and economical tear-strip means are provided for detachably securing the cover of the carton to the front wall member having means provided to compensate for registry errors in the printing, cutting, and scoring of the carton blanks.

It is to be understood that the invention is not limited to the exact details of construction, operation, or exact materials or embodiments shown and described, as bvious modifications and equivalents will be apparent to one skilled in the art, and the invention is therefore to be limited only by the scope of the appended claims.

We claim:

1. A carton formed of an integral blank cut and scored to provide a bottom member, a front wall member hingedly connected to one edge of said bottom member, a rear wall member hingedly connected to the other edge of said bottom member, and end flaps hingedly connected to the ends of said members, a cover hingedly connected to the upper edge of said rear Wall member provided with cover flaps comprising cover end wall panels and a cover front wall panel, and detachable means adhesively aflixing said cover front wall panel to said front wall member comprising a strip adhesively aflixcd to said front wall member at a plurality of isolated adhesive areas, the outer surface of said front wall member being provided with primary cut scores surrounding at least a substantial portion of said adhesive areas, and a plurality of secondary cut scores, associated with said primary cut scores and having a generally transverse component, spaced apart from the leading edges of said primary cut scores, said primary and secondary cut scores penetrating the surface of said front wall member but extending only partially into the thickness thereof, whereby clean separation of said tear strip at said adhesive areas is facilitated when said tear strip is removed.

2. A carton formed of an integral blank cut and scored to provide a bottom member, a front Wall member hingedly connected to the other edge of said bottom member, a rear wall member hingedly connected to the other edge of said bottom member, and end flaps hingedly connected to the ends of said members, a cover hingedly connected to the upper edge of said rear wall member provided with cover flaps comprising cover end wall panels and a cover front wall panel, and detachable means adhesively affixing said cover front wall panel to said front wall member comprising a tear strip having a continuous strip of an adhesive over a substantial portion of the inner surface thereof, and an adhesive resist coating applied to the outer surface of said front wall member over the area engaged by said adhesive except at isolated adhesion areas free of said adhesive resist coating whereat said tear strip is adhesively aflixed to said front wall member, the outer surface of said front wall member being provided with primary cut scores surrounding at least a substantial portion of said adhesive areas, and a secondary cut score associated with each of said primary cut scores and having a generally transverse component spaced apart from the leading edge of said primary cut score, said primary and secondary cut scores penetrating the surface of said front wall member but extending only partially into the thickness thereof, whereby clean separation of said tear strip at said adhesive areas is facilitated when said tear strip is removed.

3. A carton according to claim 2 wherein said tear strip is connected to said cover front Wall panel at a severance line which comprises a plurality of slits each having one component substantially colinear with like components of the remaining slits, said colinear slits being spaced apart to define bridges retaining said tear strip in position attached to said cover front wall panel, selected members of the colinear components of said slits being elongated to provide bridges of diminished length positioned generally laterally of the leading edge of said adhesive areas.

4. An integral blank for forming a carton cut and scored to provide a bottom member, a front wall member hingedly connected to one edge of said bottom member, a rear wall member hingedly connected to the other edge of said bottom member, and end flaps hingedly connected to the ends of said members, a cover hingedly connected to the upper edge of said rear wall member provided with cover flaps comprising cover end wall panels and a cover front wall panel, and detachable means adapted for adhesively affixing said cover front wall panel to said front wall member comprising an adhesive strip adapted to be adhesively afiixed to said front wall member at a plurality of isolated adhesive areas, the outer surface of said front wall member being provided with primary cut scores surrounding at least a substantial portion of said adhesive areas, and a plurality of secondary cut scores, associated with said primary cut scores and having a generally trans verse component, spaced apart from the leading edges of said primary cut scores, said primary and secondary cut scores penetrating the surface of said front wall member but extending only partially into the thickness thereof, whereby clean separation of said tear strip at said adhesive areas is facilitated when said tear strip is removed from the assembled and sealed carton.

5. An integral blank according to claim 4 wherein said secondary cut scores are curvilinear and positioned within the areas defined by said primary cut scores.

6. An integral blank according to claim 4 wherein said secondary cut scores are in the form of straight lines transversely arranged within the areas defined by said primary cut scores with their ends engaging said primary cut scores.

7. An integral blank according to claim 4 wherein said secondary cut scores are curvilinear and positioned without the areas defined by said primary cut scores.

8. An integral blank according to claim 4 wherein said primary and said secondary cut scores are oval-shaped and said secondary cut scores are positioned within said primary cut scores.

9. An integral blank according to claim 4 wherein said tear strip is connected to said cover front wall panel at a severance line which comprises a plurality of slits each having one component substantially colinear with like components of the remaining slits, said colinear slits being spaced apart to define bridges retaining said tear strip in position attached to said cover front wall panel, selected members of the colinear components of said slits being elongated to provide bridges of diminished length positioned generally laterally of the leading edge of said adhesive areas.

10. An integral blank according to claim 4 wherein at least some of said slits also have an oblique component.

11. An integral blank according to claim 9 wherein the first bridge at the end of said tear strip at which tearing is initiated is of reduced length to facilitate said initiation.

1 1 12. An integral blank according to claim 4 wherein a wax or plastic coating is applied to at least the outer surface of said carton blank except at isolated areas including said primary cut scores, which areas remain free of said coating.

References Cited by the Examiner UNITED STATES PATENTS Re. 25,876 10/1965 Buttery et a1.

1,963,639 6/1934 Ahlquist 22980 2,083,158 6/1937 Ramsey 22985 X Berkowitz 22985 X Meyers 22937 Egleston et a1 229-17 Larson 2295 1 Holmes 22951 FOREIGN PATENTS Great Britain.

0 JOSEPH R. LECLAIR, Primary Examiner. 

1. A CARTON FORMED OF AN INTEGRAL BLANK CUT AND SCORED TO PROVIDE A BOTTOM MEMBER, A FRONT WALL MEMBER HINGEDLY CONNECTED TO ONE EDGE OF SAID BOTTOM MEMBER, A REAR WALL MEMBER HINGEDLY CONNECTED TO THE OTHER EDGE OF SAID BOTTOM MEMBER, AND END FLAPS HINGEDLY CONNECTED TO THE ENDS OF SAID MEMBERS, A COVER HINGEDLY CONNECTED TO THE UPPER EDGE OF SAID REAR WALL MEMBER PROVIDED WITH COVER FLAPS COMPRISING COVER END WALL PANELS AND A COVER FRONT WALL PANEL, AND DETACHABLE MEANS ADHESIVELY AFFIXING SAID COVER FRONT WALL PANEL TO SAID FRONT WALL MEMBER COMPRISING A STRIP ADHESIVELY AFFIXED TO SAID FRONT WALL MEMBER AT A PLURALITY OF ISOLATED ADHESIVE AREAS, THE OUTER SURFACE OF SAID FRONT WALL MEMBER BEING PROVIDED WITH PRIMARY CUT SCORES SURROUNDING AT LEAST A SUBSTANTIAL PORTION OF SAID ADHESIVE AREAS, AND A PLURALITY OF SECONDARY CUT SCORES, ASSOCIATED WITH SAID PRIMARY CUT SCORES AND HAVING A GENERALLY TRANSVERSE COMPONENT, SPACED APART FROM THE LEADING EDGES OF SAID PRIMARY CUT SCORES, SAID PRIMARY AND SECONDARY CUT SCORES PENETRATING THE SURFACE OF SAID FRONT WALL MEMBER BUT EXTENDING ONLY PARTIALLY INTO THE THICKNESS THEREOF, WHEREBY CLEAN SEPARATION OF SAID TEAR STRIP AT SAID ADHESIVE AREAS IS FACILITATED WHEN SAID TEAR STRIP IS REMOVED. 